Lempa River Basin Wet-environment Evapotranspiration and Precipitation Standardized Index (WEPSI) Data

As drought is a major threat to global agriculture its assessment and monitoring are essential. We introduced the Wet-environment Evapotranspiration and Precipitation Standardized Index (WEPSI) for drought assessment and monitoring. WEPSI considers precipitation (P) for water supply and wet-environment evapotranspiration (ETw) for water demand. We used the asymmetric complementary relationship to calculate ETw using actual (ETa) and potential evapotranspiration (ETp). WEPSI is tested in the transboundary Lempa River basin located in the Central American dry corridor. ETw is estimated based on evapotranspiration data calculated using the Water Evaluation And Planning (WEAP) system hydrological model. To investigate the performance of our introduced drought index, we compared it with two well-known meteorological indices (SPI and SPEI), together with a hydrological index (Standardized Runoff Index). This resource includes data used to obtain the reported results and the results themselves.